Ascorbic acid asymmetric synthesis

Example 9.8 This is an example of the creative use of a chiral building block from nature in the synthesis of (+)-sertraline (15,46 )-TM 9.3. Asymmetric synthesis starts from D-glyceraldehyde available by oxidative splitting of maimose or ascorbic acid [23]. Protected as acetal 17, this aldehyde is coupled to -alkene 19 with phosphonate 18, a reagent in the Homer-Wads worth-Emmons reaction (Scheme 9.13). 

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