Date of Award

2003

Document Type

Honors Thesis (Open Access)

Department

Colby College. Chemistry Dept.

Advisor(s)

Dasan M. Thamattoor

Second Advisor

Jeffrey A. Katz

Abstract

This thesis reports the first complete synthesis of monriporynes A and B. isomeric diacetylenes that bear α, β unsaturated ketone functionalities. Recently isolated from the stony coral Montipora sp. these compounds are reported to possess in vitro cytotoxic activity against several human solid tumor cells. We have synthesized both isomers in three simple steps. In the first step, l-iodononyne was prepared by reacting 1-nonyne with N-iodosuccinimide and a catalytic amount of silver nitrate. This iodoalkyne was then coupled with propargyl alcohol using copper iodide as the catalyst to give 2,4dodecadiynyl alcohol. Finally, the diacetylenic alcohol was subjected to the Swern oxidation and the resulting aldehyde trapped via a Wittig reaction with 1lriphenylphosphoranylidene-2-propanone to afford montiporyne A. Upon standing at room temperature for a few hours. montiporyne A partially isomerized to its isomer, montiporyne B. The two isomers were separated by flash chromatography and characterized by NMR, IR, and GC-MS. The "one-pot" conversion of a primary alcohol to an α, β unsaturated ketone, using the Swern and Wittig reactions, proved to be an efficient procedure in the synthesis of montiporynes A and B. While a number of protocols have been developed to convert alcohols to α, β unsaturated esters via oxidation followed by an in situ Wittig olefination, not much is known about the utility of this "one-pot", two-step process to prepare α, β unsaturated ketones. Thus a Dumber of structurally diverse primary alcohols were subjected to the Swern/Wittig sequence to investigate the scope and limitations of the method. Although preliminary results are promising much work still remains to be done to optimize the yields of products.

Keywords

Synthesis, Montiporynes

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