Methods to prepare lactic acid from acetaldehyde

I got one method [here](using acetaldehyde and carbon monoxide)[1](http://pubs.acs.org/doi/abs/10.1021/i360033a018).


But is there any alternative method (using specific catalyst)?




A fairly simple two step synthesis involves nucleophilic addition of $\ce{HCN}$ to the carbonyl group and then aqueous hydrolysis of the nitrile to yield the carboxylic acid product.


[![enter image description here](https://i.stack.imgur.com/vGz6n.jpg)](https://i.stack.imgur.com/vGz6n.jpg)


 7

Acetylene + $\ce{HCN-Ba(CN)2}$ → vinyl cyanide 


Vinyl cyanide - hydrolysis → acetaldehyde cyanohydrin


Acetaldehyde cyanohydrin - dil HCl → lactic acid 


 -1