I feel now, after creating this blog, that I should be making posts in some orderly manner, so I have decided to start off with a series of posts relating to certain reactions of Annulation processes: Those of which result in the formation of a ring after a number of reaction sequences.
In my first of this series, I would like to make the introduction to the Robinson Annulation, an important reaction for the synthesis of biologically significant steroids. The first step of this technology is relevant in calling it a Michael addition, where a ketone enolate is created by a base called DBU (Diazabicycloundecene - a good base that does not perform a nucleophilic addition) and it performs a 1,4-addition on a conjugated carbonyl (in this case a ketone). The following step is an aldol reaction being instigated by adding a strong base (NaOMe) to deprotonate the alpha carbon on the newly added ketone, for it then to nucleophilically attack the C=O. It then goes through a spontaneous dehydration elimination of the alcohol formed in that process to eleviate a conjugated system once again.
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