A new spiro-β-methylene-γ-lactone annulation reaction is addressed for the synthesis of 4- methylene-2-oxaspiro [4.5] decan-1-one and its derivatives. 2-Cyclohexylidene-3- trimethylsilylprop-1-yl pivalate, obtained from cyclohexanone, was hydroxymethylated followed by desilylation to afford 2-[(1-hydroxymethyl) cyclohexyl] prop-2-en-1-yl pivalate and its-1-en-1-yl isomer. The former was oxidized to carboxylic acid followed by ...
![4-methylidene-2-oxaspiro[4.4]nonan-1-one Structure](https://image.chemsrc.com/caspic/022/57429-72-8.png)
![2-[(1-hydroxymethyl)cyclopentyl]prop-2-en-1-yl pivalate Structure](https://image.chemsrc.com/caspic/112/468773-77-5.png)