Total Synthesis of Sekothrixide Strategically Utilizing Regioselective Coupling of TMS-Protected Epoxy sec-Alcohol
Daisuke Katsumi1, Kazuki Nakasone1, Naoki Terayama1
1Department of Applied Chemistry , Kogakuin University , Nakano 2665-1 , Hachioji , Tokyo 192-0015 , Japan.
Abstract:
A new efficient synthesis of sekothrixide was established on the basis of our developed regioselective coupling of epoxy sec-alcohol with Gilman reagent guided by a TMS group. The new synthetic route allowed an overall yield of 6.3% (26 steps) from optically active 3-silyloxy-2-methylaldehyde.
Related Concept Videos
Acid Halides to Ketones: Gilman Reagent
As shown below, the mechanism proceeds in two steps. First, one of the alkyl groups of the reagent acts as a nucleophile and attacks the acyl carbon of the acid chloride to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen...
Protection of Alcohols
Protection
It defines a protecting group as the masking agent to make the more reactive species inert to a given set of conditions. This concept is depicted via the illustration of liquid flow through different outlets in an assembly of pipes. The analogy helps to understand the role...
Ethers from Alcohols: Alcohol Dehydration and Williamson Ether Synthesis
Ethers can be prepared from organic compounds by various methods. Some of them are discussed below,
Preparation of Ethers by Alcohol Dehydration
In this method, in the presence of protic acids, alcohol dehydrates to produce alkenes and ethers under different conditions. For example, in the presence of sulphuric acid, dehydration of ethanol at 413 K yields ethoxyethane, whereas it yields ethene at 443 K.
Regioselectivity of Electrophilic Additions-Peroxide Effect
Strategies of Self-Presentation I: Strategic Self-Presentation
Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.


