Schema.org itemtype error, need advice Options

[Boot]

I'm trying to add microdata to our website and am getting an error when testing the code in Yandex.

CODE

<div class="responsive-container" itemscope="itemscope" itemtype=“http://schema.org/VideoObject”>
<meta itemprop="duration" content="T2M14S" />
<meta itemprop="caption" content="The Doctor of Pharmacy Program at Manchester University" />
<meta itemprop="uploadDate" content="2016-8-16" />

<iframe itemprop=”embedUrl” src="https://www.youtube.com/embed/aPhigRk9mms?rel=0" allowfullscreen="" frameborder="0" height="315" width="560"></iframe></div>

Error: WARNING: itemtype “http://schema.org/VideoObject” not recognized by validator

On schema.org it shows this exact itemtype. Any ideas where my mistake is?