Возможно ли это с помощью flexbox

* {
  margin: 0
}

.topBox,
.leftBox,
.rightBox {
  padding: 5px;
}

.topBox {
  background: green
}

.leftBox {
  background: red
}

.rightBox {
  background: yellow
}

.row {
  display: flex
}

.leftBox,
.rightBox {
  width: 50%;
  box-sizing: border-box;
}

@media (min-width: 768px) {
  .wrapper {
    position: relative;
    padding-right: 30%;
    min-height: 100vh;
  }
  .rightBox {
    position: absolute;
    right: 0;
    top: 0;
    bottom: 0;
    overflow: auto;
    width: 30%;
  }
  .leftBox {
    width: 100%
  }
}

<div class = "wrapper">
  <div class = "topBox">
    It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here,
    content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their default model text, and a search for 'lorem ipsum' will uncover many web sites still in their infancy. Various
    versions have evolved over the years, sometimes by accident, sometimes on purpose (injected humour and the like).
  </div>
  <div class = "row">
    <div class = "leftBox">
      It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here,
      content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their default model text, and a search for 'lorem ipsum' will uncover many web sites still in their infancy. Various
      versions have evolved over the years, sometimes by accident, sometimes on purpose (injected humour and the like).
    </div>
    <div class = "rightBox">
      It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here,
      content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their default model text, and a search for 'lorem ipsum' will uncover many web sites still in their infancy. Various
      versions have evolved over the years, sometimes by accident, sometimes on purpose (injected humour and the like).
    </div>
  </div>
</div>

* {margin: 0; padding: 0; box-sizing: border-box}

#container {
  display: flex;
  flex-flow: column wrap;
  position: relative;
  width: 500px;
  height: 500px;
  padding: 5px;
  border: 2px solid;
}

#container > div {
  margin: 5px;
  border: 2px solid;
}

#green {background: green; flex: 0 1 calc(50% - 10px); position: relative}
#red {background: red; flex: 0 1 calc(50% - 10px)}
#yellow {background: yellow; flex: 1}

@media (max-width: 600px) {
  #green {flex: 1}
  #red {width: calc(50% - 15px); height: calc(50% - 5px); position: absolute; left: calc(50%); bottom: 5px}
  #yellow {flex: initial; width: calc(50% - 10px); height: 50%}
}

<div id = "container">
  <div id = "green">Green</div>
  <div id = "red">Red ^^^^ this space is the issue</div>
  <div id = "yellow">Yellow</div>
</div>

.container {
  display: flex;
  padding: 10px;
  flex-wrap: wrap;
  justify-content: space-between;
}
.left-container {
  width: 60%;
  min-height: 400px;
}
.green-box, .red-box, .yellow-box {
  width: 100%;
  margin-bottom: 1%;
}
.green-box {
  background: green;
  height: 50%;
}
.red-box {
  background: red;
  height: 49%;
}
.right-container {
  width: 39%;
  min-height: 400px;
}
.yellow-box {
  background: yellow;
  height: 100%;
}

<div class = "container">
  <div class = "left-container">
    <div class = "green-box"></div>
    <div class = "red-box"></div>
  </div>
  <div class = "right-container">
    <div class = "yellow-box"></div>
  </div>
</div>

*{box-sizing:border-box;}
#container {
display: flex;
width: 500px;
flex-wrap: wrap;
flex-direction: column;
height: 300px;
}
#green{background: green; width: 70%; height: 100px; }
#yellow{background: yellow; width: 30%; height: 200px; }
#red{background: red; width: 70%; height: 70px; }

@media screen and (max-width: 600px){
#container { flex-direction: row; max-width: 100%; height: auto; }
#green{width: 100%; }
#yellow{width: 50%; }
#red{width: 50%; height: auto; }
}

<div id = "container">
  <div id = "green"></div>
  <div id = "red"></div>
  <div id = "yellow"></div>
</div>