The Retro-Synthetic Approach

In fact, the overall perspective and conception of a synthesis commences with a careful logical dissection of the tai et-drug-molecular skeleton into S3mthons. However, the disconnection of a bond within a monocyclic system shall be a retro-synthetic ring-opening phenomenon, otherwise termed as the retro-synthetic approach. Likewise, the disconnection of a bond caused in a bridged-structure would ultimately produce either a mono- or a di- substituted monocyclic structure. Sometimes, it may also be possible to accomplish two-bond disconnections taking place almost simultaneously. 

A double-line arrow is invariably used to indicate a reaction written backwards—the actual reaction in reverse. The retro-S3mthetic approach may be expaliated with the help of 

Salient Features. The various salient features of the retro-S3mthetic approach of vitamin A are, namely  

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Nicolaou s Synthesis. Nicolaou s synthesis also involves a B-ring closure to connect the A and C rings.33 The retro synthetic approach is depicted in Scheme 7-59. 

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