In sweetgum (Liquidambar styraciflua), sinapaldehyde arises in two steps from coniferyl aldehyde beginning with hydroxylation mediated by coniferyl aldehyde 5-hydroxylase.  The diphenol is then methylated at the 5-OH by the action of caffeate O-methyltransferase.
Sinapaldehyde is reduced to the alcohol by the action of dehydrogenase enzymes. In Arabidopsis thaliana, the enzyme dihydroflavonol 4-reductase uses NADP to reduce sinapaldehyde to sinapyl alcohol.
It is found in Senra incana (Hibisceae). It is a low molecular weight phenol that is susceptible to extraction from cork stoppers into wine.