Dilithiated 1‐tetralone oxime was condensed with several electron enriched aromatic aldehydes, such as 4‐methoxybenzaldehyde or lithiated 4‐hydroxybenzaldehyde, followed by acid cyclization to new tetrahydronaphthisoxazoles, 3,3a,4,5‐tetrahydronaphth[1,2‐c]isoxazoles, with a trans geometry of the C3‐H and C3a‐H protons that was confirmed by X‐ray single crystal analysis.