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Oxidative cleavage of 1,2:5,6‐di‐0‐cyclohexylidene‐D‐mannitol (2) with lead (IV) acetate yields (R)‐2,3‐0‐cyclohexylideneglyceraldehyde, which was transformed by oxidation and esterification into methyl 2,3‐0‐cyclohexylideneglycerate. Grignard reaction with various alkylmagnesium halides followed by acid‐catalyzed removal of the acetal group and reaction with p‐toluenesulfonyl chloride in pyridine furnished the title compounds (8a–d) in good chemical overall yield and high enantiomeric purity. The compounds were prepared as intermediates for the synthesis of a series of steroids with a modified side chain.

Homochiral 3‐alkylated (2R,3R)‐ and (2R,3S)‐2,3‐dihydroxyalkyl p‐toluenesulfonates (9 and 10) are essential building blocks for vitamin D3 metabolites with a modified side chain. Nine of these compounds have been prepared starting from (R)‐2,3‐O‐cyclohexylideneglyceraldehyde (1) by addition of alkylmagnesium halides, Jones oxidation of the obtained diastereomeric alcohols 2 and 3 to the corresponding ketones 4, and a second addition of alkylmagnesium halides, followed by hydrolytic removal of the cyclohexylidene group and selective tosylation. The opposite diastereoselectivity of the two Grignard reactions is discussed.

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JavaScript has become more and more popular in recent years because its wealthy features as being dynamic, interpreted and object-oriented with first-class functions. Furthermore, JavaScript is designed with event-driven and I/O non-blocking model that boosts the performance of overall application especially in the case of Node.js. To take advantage of these characteristics, many design patterns that implement asynchronous programming for JavaScript were proposed. However, choosing a right pattern and implementing a good asynchronous source code is a challenge and thus easily lead into less robust application and low quality source code. Extended from our previous works on exception handling code smells in JavaScript and exception handling code smells in JavaScript asynchronous programming with promise, this research aims at studying the impact of three JavaScript asynchronous programming patterns on quality of source code and application.