Boron and diols

How does the Boron react with diol? Is this the right way it reacts? What kind of interaction is this? 


Why does such a reaction occur?


[![enter image description here](https://i.stack.imgur.com/y34hJ.png)](https://i.stack.imgur.com/y34hJ.png)




Your starting material (**1**) is 2,1-Benzoxaborol-1(*3H*)-ol. This can be considered as the intramolecular half-**ester** of 2-hydroxymethyl-phenylboronic acid.


[![enter image description here](https://i.stack.imgur.com/iQr7M.png)](https://i.stack.imgur.com/iQr7M.png)


Under suitable conditions, esterification of **1** with the diol will initially yield the ester **2**. 


Transesterification, that is closing one five-membered ring while opening the other in this case, may lead to **3**.


 5

Boron is a Levis acid while he alcohol is considered a Levis base. It is able to have a reaction between them. The problem is that the structure of the product of reaction do not show a -OH group.


 -3