Synthetics
Ethyl lactate has a mild, ethereal-buttery scent that can work well in some fragrances, but may not be universally desirable.
Mosciano, Gerard P&F 18, No. 4, 51, (1993): Sweet, fruity, acidic, etherial with a brown nuance
Luebke, William tgsc, (1985): Sharp tart fruity buttery butterscotch
Pell Wall Perfumes: Sweet, fruity, ethereal, buttery, butterscotch
It is worth noting that although arctander describes this as a mild’ smelling material, other commentators (including william luebke of the good scents company) have described it as having high’ odour impact and this perfumer would certainly agree that while it isn’t harsh or overwhelming, it is not material you’re going to have difficulty detecting on a smelling strip.