Hi I have used below code ,it will provide you with shadow you want.
UIBezierPath *shadowPath = [UIBezierPath bezierPathWithRect:_viewShadow.bounds];
_viewShadow.layer.masksToBounds = NO;
_viewShadow.layer.shadowColor = [UIColor blackColor].CGColor;
_viewShadow.layer.shadowOffset = CGSizeMake(10.0f, 5.0f); /*Change value of X n Y as per your need of shadow to appear to like right bottom or left bottom or so on*/
_viewShadow.layer.shadowOpacity = 0.5f;
_viewShadow.layer.shadowPath = shadowPath.CGPath;
Also masksToBounds is imp as it disables the clipping of sublayers that extend further than the view's bounds. If you put it YES then you won't see shadow as it clips sublayer where else in NO it allow to extent layer.